Knife Review: Coast Rapid Response 3.90

Knives generally aren’t my thing. I’m a gun guy, and they’re my tool of choice when it comes to self defense. But with my side job as an EMT there have been a number of times where having a knife handy makes all the difference . . .

I remember one incident shortly before I left Fairfax where we had to cut a drunk driver out of his clothes to assess a heavily bleeding wound and having my knife handy saved us a good 30 seconds of poking around the bag for the trauma shears. It also helped with the hanging woman, but we won’t go into that one.

The point is that a sharp and reliable blade is something I’ve come to include in my daily loadout. Every morning I grab my watch, my wallet, cell phone, keys, knife and gun off the nightstand and walk out into the world ready to face any challenge. Considering my hobbies (shooting and pulling people out of car wrecks) I have a pretty high standard when it comes to the cutlery I carry.

So when I ran across the guys at Coast (full disclosure: I originally only stopped by their SHOT Show booth for the free beer) and they told me about their new “Rapid Response” knives I had to try one out. So they handed me their Rapid Response 3.90 right then and there and I’ve been carrying it ever since.

There are a few features about this knife that make it stand out to me. The first of which is the manual safety on the side of the knife.

When I was at SHOT it had only been a few weeks since I had gone out and become the scourge of the wildlife on Tyler’s ranch in Texas. I learned many things that weekend, the most interesting of which was how to field dress a deer.

For the uninitiated, “field dress” is a euphemism for disemboweling the freshly killed creature in an effort to preserve the meat. It involves opening the abdomen, splitting the sternum, cracking open the pubic symphysis and slicing out the animal’s internal organs. In order to accomplish the task you need a very sharp and very durable knife (and a Sawsall doesn’t hurt, either). Tyler had a trick for cracking open the cartilage that involved using the back of the knife blade as a wedge. That made me slightly nervous, though, that the knife was going to snap closed on his fingers.

The manual safety on this knife acts as a backup to the standard locking mechanism, providing a little extra piece of mind when you need it. And if you don’t want to use it you don’t have to. But there’s another reason I like the manual safety: the assisted opening mechanism.

I had never seen an assisted opening knife before SHOT, but after the show I felt like I had sat through a graduate course on the things. Assisted opening knives seem to be the “new thing” that more knife manufacturers are building into their blades. The basic principle is that the user opens the knife just a tiny bit and then an internal spring automatically opens it the rest of the way. It’s a legal loophole around anti-switchblade laws, and while I never felt that I absolutely needed that feature on my knife, it definitely makes opening the knife easier.

The only problem is that I had a small obsession with the idea that the knife was going to get snagged on something, open up in my pocket and slice the crap out of my leg. But thanks to the manual safety that idea was put to rest.

The other thing I liked about the knife is the profile of the blade. Some knives come with a crazy curving blade that’s impossible to sharpen using my old Boy Scout issue sharpening stone. But the Coast knife uses a simple straight main cutting surface with a gently sloping curve towards the tip.

There are, however, some issues with the knife.

The pocket clip leaves a little to be desired. I may have been spoiled by Benchmade’s flawless pocket clip design, but this one is a little tough to unhook from my station pants when I’m in a hurry. Which is just about every time I need the thing.

Complaint #2 concerns the durability of the blade. I’ve just recently moved to Texas, so I figured the perfect test of this knife was to use it to cut up all the cardboard boxes. It made it through about half of them while still razor sharp, but then it lost its edge. My Benchmade opened and destroyed an identical number of boxes but kept its razor sharp edge to the end. Admittedly it didn’t last much longer and both knives have needed a good sharpening, but it’s the little differences that matter the most.

The last issue I had was that the knife is a little too long for my taste. It clocks in at just under 4 inches, which makes it the longest folding knife I’ve ever owned. I asked for that on purpose — I wanted to try it out and see if I preferred the small blades or the larger ones better. And it turns out that I lean toward the smaller ones. But never fear: Coast makes a smaller version of this very knife that’s nearly identical and probably closer to my ideal length.

So what’s the verdict? Well, when you consider the totality of the evidence I still think it’s a fine knife for the money. It has some nifty features, and at $44 MSRP it’s not going to break the bank. If you’re looking for a good general purpose knife this definitely warrants a peek.

Coast Rapid Response 3.90

Assisted Open
Liner Lock
Blade Length: 3.9 in.
Overall: 8.75 in.
Weight: 4.8 oz.
MSRP: $44

Overall Rating: * * *
Not the perfect knife, but good enough.


  1. jwm says:

    I carry a Kershaw 1550 ST as my everyday carry knife. It’s assisted opening and has the half serrated blade. I open a lot of cardboard boxes and dispose of them. Straight edged blades simply won’t cut it, pardon the pun. So far this knife has held up well and at 36 bucks at the wally world I can’t complain.

    My other routine carry knife is usually some varient of the SAK. I have more than 1 from victorinox and wenger.

  2. Aharon says:

    My first comment here.

  3. chris says:

    what kind of steel?

  4. mark says:

    Re the durability of the edge, that almost certainly has to do with the 5Cr15Mov steel–it’ll take a nice edge but won’t hold it under the kind of hard use you gave it. OTOH, it should sharpen up much easier than some of the higher end steels that Benchmade uses.

    Re the assisted opening mechanisms, I’m rather partial to Kershaw’s speed safe system. I have a Volt II and the “flipper” doubles, when the knife is opened, as a bit of a finger guard. It also uses the 8Cr13MoV steel, which gets pretty good marks for edge retention–Spyderco uses it on some of their knives like the Tenacious, for that reason.

  5. SubZ says:

    Wasn’t familiar with Coast Knives, but may try this one’s brother (RX321). Currently carry a CRKT Ignitor-T/with Veff serrations.

    Cool site, look forward to reading more 🙂

  6. 2hotel9 says:

    This looks like a not too bad utility knife. From the pics I think the clip would be nice, I like one that is close to the end of the case, though I prefer it on the hinge end, that is a more natural place when pulling it from pocket/belt to open. I really like the edge, kinda tired of the whole serrated thing. I hardly ever use that section of a blade.

    I’ll have to check and see who near me carries Coast blades so I can do a hands on.

  7. MD Matt says:

    Try the Kershaw R.A.M.
    It’s by far my favorite for every day carry when I’m not looking to do big projects.
    I’m a big fan of cold steel, but most of their stuff is 4 inches, so isn’t that great for casually walking around for me (especially since my favorite from them is my old ak47.)
    The R.A.M. has the side safety, opens normally or as an assisted opener, has no annoying liner lock to deal with, and requires real force to open (making it damn near impossible to open by accident.)
    It also has a straight blade, which I’ve become really attached to after several years of funky curves, geometries, and half serrations.
    It’s simple and effective.

  8. Paul W says:

    Looking at the price difference between this and most Benchmade knives I think I’ll stick with this…holy crap. 100+ for a pocket knife is a bit much for my taste.

    1. Dogman says:

      The difference is that the Benchmade knives for $100+ are actually worth it. Knives like this Coast are not. You’ll end up buying more than $100 worth of these cheap knives for less service than you will get out of one quality knife like a Benchmade.

      1. 2hotel9 says:

        Or a Buck 110.

    2. Nathan says:

      I spent $700 on one knife. Twice

  9. After seeing some Coast Knives at Blade, I was less than impressed. The fit and finish is just sub par in my opinion. Add to this the middling steel, and I just don’t feel like they are a good bang for the buck, even at a budget price point.

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Knife Review: Coast Rapid Response 3.90

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